The Geometry and Petrogenesis of Dolomite Hydrocarbon Reservoirs
The wide distribution of dolomite rocks in North American, Middle- and Far-Eastern hydrocarbon reservoirs is reason enough for their intensive study. In this volume dolomite enthusiasts review progress and define the current boundaries of dolomite research, related particularly to the importance of these rocks as reservoirs. As might be expected, reviews provide critical analyses of past ideas on origins and why many are no longer tenable. Discussions range between conceptual models and numerical simulations of the flow paths of dolomitizing fluids, geochemical modelling, and microbial mediation. Case studies from areas as diverse as North America, the Middle East, SE Asia and Australia provide a solid background but illustrate important differences in views on the origins of these enigmatic rocks.
Early dolomitization and fluid migration through the Lower Carboniferous carbonate platform in the SE Irish Midlands: implications for reservoir attributes
Published:January 01, 2004
Zs. R. Nagy, J. M. Gregg, K. L. Shelton, S. P. Becker, I. D. Somerville, A. W. Johnson, 2004. "Early dolomitization and fluid migration through the Lower Carboniferous carbonate platform in the SE Irish Midlands: implications for reservoir attributes", The Geometry and Petrogenesis of Dolomite Hydrocarbon Reservoirs, C. J. R. Braithwaite, G. Rizzi, G. Darke
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Shallow-marine, Lower Carboniferous carbonate sequences of the SE Irish Midlands, close to the Leinster Massif, are intensely dolomitized. Fine-crystalline (<50 μm), planar-s (subhedral) dolomite is associated with evidence for evaporites, typical of arid peritidal sequences. However, stable isotope data suggest a diagenetic overprint. Volumetrically more important medium-crystalline (50–200 μm), planar-s and minor planar-e (euhedral) dolomites were precipitated from slightly modified Lower Carboniferous seawater. These dolomites replace open-marine intraclastic and bioclastic packstones and grainstones.
Length-slow, fibrous quartz partially replaces crinoids and fills dissolution cavities beneath peritidal strata. Associated dolomites are gradually enriched in 18O downward through the underlying strata,...